1. Field of the Invention
The present invention relates to a multilayer circuit board that is a laminate including a plurality of insulating substrates and conductive patterns, and a method for manufacturing the multilayer circuit board.
2. Description of the Related Art
A signal line utilizing a multilayer circuit board is practically used for transmitting a high-frequency signal. For example, JP 4962660 B1 discloses a structure in which a laminate formed by stacking insulating substrates is provided, and a signal conductor and ground conductors are formed on the laminate.
According to the signal line of JP 4962660 B1, the signal conductor is disposed at an intermediate position in the lamination direction. Two ground conductors are disposed at positions to sandwich the signal conductor in the lamination direction. The two ground conductors are provided in the laminate, and are connected with each other through an interlayer connection conductor extending in the lamination direction.
According to the conventional signal line, however, it is not easy to form a conductive pattern, for example, on a side surface parallel to a lamination direction of the laminate, i.e., a surface other than the surfaces along the main surface of the insulating substrate. Particularly, it is not easy to form a complicated conductive pattern on such surfaces. In addition, as a conductive pattern provided at each part of the laminate becomes finer and more complicated, it becomes difficult to form a desired conductive pattern.